The invention relates to a cylinder-piston unit of a disposable injector, having at least one passage connecting the cylinder interior to an end-face mouth.
A cylinder-piston unit is known from DE 957 598 B. In order to prevent the formation of a tear instead of a penetration channel, a notched friction collar is formed against lateral slipping.
The object of the present invention is therefore to further increase the operational safety of a cylinder-piston unit of a disposable injector and to prevent what is called a “wet shot”.